Tuing Making box not go out of the screen problem

[jasonhan416]

The program suppose to move when i use arrow keys and i understand that
ACII 200 means up
208 means down
205 means ->
203 means <-

My problem is this
i need make a program that the box doesn't go outside the size of the screen or distort.
I need to modify it.
Please help me.

here's the code

%Declaration Section
var startpointx, startpointy : int := 0
var endpointx, endpointy : int := 50
var key : string (1)

%Set screren mode and size
setscreen ("graphics :400;400")
setscreen ("noecho")
setscreen ("ncursor")
setscreen ("offscreenonly")

procedure display
drawfillbox (startpointx, startpointy, endpointx, endpointy, 0)
drawfillbox (startpointx + 1, startpointy + 1, endpointx - 1, endpointy - 1, blue)
getch (key)
if key = chr (200) then
startpointy := startpointy + 1
endpointy := endpointy + 1
elsif key = chr (208) then
startpointy := startpointy - 1
endpointy := endpointy - 1
elsif key = chr (205) then
startpointx := startpointx + 1
endpointx := endpointx + 1
else
if key = chr (203) then
startpointx := startpointx - 1
endpointx := endpointx - 1
end if
end if
View.Update
end display

%Main program
loop
display
exit when key = chr (27)
end loop

[ecookman]

use maxx and maxy to find the max of the corners


example:

put maxx
put maxy

^
|
|

will show you the max corr. of the x and y

then an restricting it to the max corrs. i think this is done using an array of boolean

pretymuch


if {the box is in the points} = true
if {the box is outside of the points} = false {get it to stop there}


... i think

[jasonhan416]

ecookman @ Sun Dec 14, 2008 2:41 pm wrote:

use maxx and maxy to find the max of the corners


example:

put maxx
put maxy

^
|
|

will show you the max corr. of the x and y

then an restricting it to the max corrs. i think this is done using an array of boolean

pretymuch


if {the box is in the points} = true
if {the box is outside of the points} = false {get it to stop there}


... i think

oh... okay.. where in the line do you use maxx and maxy.
and cna you give me soem examples?

[DanielG]

jasonhan416, instead of using the key`s ascii value use turing`s KEY_UP_ARROW, KEY_DOWN_ARROW ..., they make the code easier to understand.

[copthesaint]

this is the easiest way and some extra keys

code:

var chars : array char of boolean loop Input.KeyDown(chars) if chars (KEY_DOWN_ARROW) then put "down" elsif chars (KEY_UP_ARROW) then put "up" elsif chars (KEY_RIGHT_ARROW) then put "right" elsif chars (KEY_LEFT_ARROW) then put "left" end if if chars (KEY_LEFT_ARROW) = true and chars (KEY_UP_ARROW) = true then put "up-left" elsif chars (KEY_LEFT_ARROW) = true and chars (KEY_DOWN_ARROW) = true then put "down-left" elsif chars (KEY_RIGHT_ARROW) = true and chars (KEY_UP_ARROW) = true then put "up-right" elsif chars (KEY_RIGHT_ARROW) = true and chars (KEY_DOWN_ARROW) = true then put "down-right" end if View.Update delay (100) end loop

plus you can alsouse numbers ('#') or letters ('a")
when using letters use lower case if you use upper case you will have to use shift while using the button